Apparatus and methods for coverlay removal and adhesive application

ABSTRACT

Apparatus and methods for synchronously removing coverlay film from an adhesive film and applying an adhesive strip cut from the adhesive film to cover one or more reject die sites and/or functional die sites on semiconductor package support elements are disclosed. Reject die sites on defective substrates are covered prior to encapsulation.

FIELD OF THE INVENTION

[0001] This invention relates generally to apparatus and methods forsemiconductor package fabrication and more specifically to apparatus andmethods for synchronous coverlay film removal and adhesive applicationto semiconductor support elements and the like.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] In semiconductor manufacture, a single semiconductor die (orchip) can be packaged within a sealed package. The package protects thedie from damage and from contaminants in the surrounding environment. Inaddition, the package provides a substantial lead system forelectrically connecting the integrated circuits on the die to theoutside world.

[0003] One type of semiconductor package 10 is illustrated in FIG. 1A.The package 10 includes a substrate 12 having a planar die attachsurface or die site 22. A semiconductor die 16 is mounted to an uppersurface of the substrate 12 on the die site 22. The die 16 is typicallyadhesively bonded to the substrate 12 with an adhesive layer 34. Anencapsulating resin 38 encapsulates the die 16.

[0004] In addition to the die site 22 on the upper surface, thesubstrate 12 includes an opposing conductor surface 24 whereinconductors 18 are formed in a required pattern. A wire bond opening 26in the substrate 12 provides access for bonding wires 28. The bondingwires 28 are connected to the conductors 18 and to bond pads (not shown)on the die 16. A glob top 40 is formed over the wires 28 for protection.

[0005] The semiconductor package 10 also includes an array of solderballs 14. The solder balls 14 are bonded to ball bonding pads 24 on theconductors 18.

[0006] As shown in FIG. 1B, the substrate 12 is initially a segment 32of a support element 30. The support element 30 includes multiplesubstrates 12 (and thus multiple die sites 22). The support element isused to fabricate multiple semiconductor packages 10. The supportelement facilitates the fabrication process in that differentoperations, such as die attach and wire bonding, can be performed at thesame time on each of the substrates. Following the fabrication of thesemiconductor packages 10 from the support element 30, the supportelement is singulated into individual semiconductor packages.

[0007] The process for packaging semiconductor dice includes matching adie to each die site on the support element. The die is attached, usingan adhesive, to the die site over the wire bond opening 26 so that thedie may be electrically connected to the substrate. Currently availablesupport elements typically include one or more substrates that aredefective or non-functional, i.e., the substrates include “reject diesites.” Individual substrates of a support element may be non-functionalfor a variety of reasons, such as faulty electrical circuitry of asubstrate. Such defect substrates of the support element cannot beutilized to fabricate a functional semiconductor package but cannot beseparated from the support element prior to processing of the othersubstrates on the support element. If the defective substrates areseparated from the support element, such action necessarily limits thenumber of substrates that may be processed at one time using theseparated support element. Thus, physical separation of defectsubstrates from the support element prior to fabrication of thesemiconductor packages is not preferred.

[0008] When functional dice are attached to the “reject die sites” ofthe support element and further are processed, the resultingsemiconductor packages are necessarily defective. This sacrificesfunctional dice, thereby increasing semiconductor package manufacturingcosts and decreasing yields. To avoid the added cost (i.e., sacrificingfunctional dice), a “reject die site” on a support element could simplybe skipped or omitted during the die attach process. Regrettably,omitting attachment of a die to a die site on a support element causesproblems during the encapsulation process.

[0009] During the encapsulation process, liquid encapsulation materialflows over and around the attached dice and substrates of the supportelement. If one or more bonding slots are left open, i.e., a die is notattached to a die site of the support element, the encapsulationmaterial flows through the uncovered opening 26. When the encapsulationmaterial flows through such openings, it contaminates dice adjacentand/or near the uncovered opening. This is known as “bleeding orflashing.” The bleeding of encapsulation material produces even moredefective semiconductor packages, further increasing manufacturing costsand lowering yield. Moreover, bleeding of the encapsulation material maystick to the mold body and contaminate the next support elementprocessed through the encapsulation machine.

[0010] In attempt to avoid (1) sacrificing functional dice by attachingthe dice on reject die sites, (2) contaminating adjacent dice and moldbodies by omitting attachment of dice to reject die sites, and (3)processing support elements that include a minimal number of substratesdue to prior separation of the defective substrates, the industry pays apremium price for support elements having no reject die sites. This alsoincreases semiconductor package manufacturing costs.

[0011] Accordingly, there is a need for a process for makingsemiconductor packages using support elements having one or more rejectdie sites without contaminating adjacent dice and without destroyingfunctional dice by attaching the dice to reject die sites. To this end,the present invention provides apparatus and methods for applying acover member, such as a strip of self-adhesive film, to the reject diesites. The cover member covers the reject die sites prior toencapsulation thereby eliminating the risk of contamination of adjacentdice on a support element during encapsulation and preserving functionaldice for use on functional die sites. Further, the apparatus and methodsof the present invention apply with a predetermined amount of forceexact lengths of adhesive film to the support element and synchronouslyremove the adhesive film's coverlay film just prior to application ofthe adhesive to the support element.

[0012] According to the present invention, reject die sites on a supportelement are covered prior to the encapsulation process using theapparatus and methods of the present invention. More specifically, theapparatus and methods of the present invention synchronously remove acoverlay film from adhesive film, cuts and applies exact lengths ofadhesive to reject die sites on the support element to act as a covermember thereon (or to allow for attachment of a separate cover memberthereto). The apparatus and methods of the present invention may also beused to synchronously remove a coverlay film from adhesive film, and tocut and apply exact lengths of adhesive to functional die sites on thesupport element for attachment of functional dice thereto. Theapplication of adhesive strips as cover members to reject die sites (orfor attachment of a separate cover member thereto) virtually eliminatesbleeding or flashing during encapsulation due to the presence of rejectdie sites while avoiding the need to sacrifice functional dice to coversuch reject die sites. The apparatus and methods of the presentinvention further provide an efficient process for removal of theadhesive film's coverlay film with the synchronous application of covermembers to reject die sites of a support element.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1A is a schematic cross-sectional view of a conventionalsemiconductor package taken along section line 1A-1A of FIG. 1B.

[0014]FIG. 1B is a plan view of a conventional support element having amultitude of exposed die sites for fabricating semiconductor packages,such as shown in FIG. 1A.

[0015]FIG. 2A is a plan view of a support element containing multipledie sites, including reject die sites that have been covered with anadhesive strip or other cover member using the apparatus and methods ofthe present invention.

[0016]FIG. 2B is a bottom view of the support element shown in FIG. 2A.

[0017] FIGS. 2C-2E are bottom views of an enlarged portion of a coveredreject die site on the support element shown in FIG. 2A.

[0018]FIG. 3 is a schematic view of the apparatus of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention provides apparatus and methods forattachment of an adhesive strip as a cover member on one or more rejectdie sites 36 of semiconductor package support elements 42 (FIGS. 2a and2B). The apparatus and method of the present invention synchronouslyremove a coverlay film from a reel of adhesive film as it cuts andapplies exact lengths of adhesive to the support element.

[0020] With reference to FIGS. 2A-2C, a representative support element42 includes multiple substrates 56. Each substrate 56 is a segment ofthe support element 42 and will subsequently be separated from theadjacent substrates 56. The support element shown in FIGS. 2A and 2Bincludes 1 8 substrates 56. However, this number is merely exemplary andthe support element 42 may include a fewer or greater number ofsubstrates 56. The substrates 56 are typically positioned side-by-sideand are integrally connected. As stated above, the support element 42facilitates the fabrication process in that different operations, suchas die attach and wire bonding, can be performed at the same time onmultiple substrates 56.

[0021] Each substrate 56 further includes a first planar surface 44(FIG. 2A) and a second planar surface 46 (FIG. 2B). In FIG. 2C a singlesubstrate 56 of support element 42 is illustrated in greater detail.Each substrate 56 further includes conductors 47 on the first surface44. Wire bonding pads 52 facilitate the wire bonding process. There is adie attach area on the second surface 46 of the substrate upon which adie (not shown) or a cover member (discussed below) will be attached.The die attach area of each substrate 56 comprises either an“operational” or “functional die site” 50 or a “defective” or “rejectdie site” 36 (FIGS. 2A and 2B).

[0022] A wire bond slot 64 extends from the first surface 44, throughthe substrate 56 to the second surface 46. Although shown rectangular inshape, wire bond slots 64 are of various sizes and shapes, dependentupon the type of semiconductor package to be fabricated therefrom. Thewire bond slots 64 provide access-for bonding wires (not shown) thatconnect die circuitry to corresponding substrate circuitry.

[0023] Each reject die site 36 of the support element 42 includes acover member 48 (cover members 48 are shown with crosshatch in FIGS.2A-2E). The cover member 48 is attached to the reject die site 36 so asto cover from about 70% to about 100% of the corresponding wire bondslot 64 on the die site. The wire bond slot 64 is covered to preventcontamination through the slot during the encapsulation process. (Thesupport member 42, wire bond slots 64, and die sites 36, 50 areillustrated in FIGS. 2A-2E prior to formation of a solder mask, solderballs or an encapsulation resin that complete formation of asemiconductor package.)

[0024] Cover member 48 may comprise any sufficiently rigid material thatcan be adhered to first surface 44 of the support element 42. Of course,cover member 48 preferably will not comprise a material that wouldcontaminate or otherwise negatively impact the operation of a completedsemiconductor package. The cover member 48 material must be able towithstand encapsulation pressures, typically from about 100 psi to about1800 psi. For example, cover member 48 may comprise single-sided ordouble-sided pressure-sensitive film, such as KAPTON™ film (availablefrom Precision PCB Services, Inc., of Santa Clara, Calif.) ortemperature-sensitive film, such as ABLESTIK™ film, (SKU No. RP444-14available from National Starch and Chemical Co., of Bridgewater, N.J.).Alternatively, the cover member 48 may comprise a non-functional orreject die.

[0025] Cover member 48 is preferably relatively specifically attached tocover a majority of the wire bond slot 64 opening. The percentage ofcoverage of the wire bond slot 64 with the cover member 48 depends uponthe encapsulation material to be used and the width of the wire bondslot 64.

[0026] Each functional die site 50 of support element 42 will have a die(not shown) attached thereto, to cover wire bond slot 64. The supportelement 42 illustrated in FIGS. 2A and 2B is shown prior to attachmentof a die. Functional or operational dice (not shown) are attached tofunctional die sites 50 only.

[0027] As shown in FIG. 2A, the support element 42 also includes one ormore indexing openings 58 formed through one or more of the substrates56, proximate longitudinal edges of the support element. The indexingopenings 58 permit support element 42 to be handled by automatedtransfer mechanisms associated with chip bonders, wire bonders, molds,trim machinery, etc. Additionally, support element 42 may includeseparation openings 60 to facilitate singulation of individualsubstrates 56 from support element 42 after formation of thesemiconductor packages.

[0028] Referring to FIG. 3, the adhesive dispensing apparatus 100 of thepresent invention applies adhesive strips to the support element 42 tofunction as the cover member 48, to connect a separate cover member 48thereto (e.g., a reject die), or to attach a functional die thereto. Asdiscussed above, cover members 48 are attached to reject die sites andfunctional dice are attached to functional die sites. The apparatus andmethod of the present invention may be used to attach adhesive strips toreject die sites and functional die sites. Adhesive film 106 typicallyincludes a thin layer of adhesive 116 and typically a ridged coverlayfilm 112. The coverlay film 112 separates the adhesive from itself whenthe adhesive is spooled on a reel 104.

[0029] In general, the adhesive dispensing apparatus 100 of the presentinvention comprises a reel of adhesive (or “film reel”) 104, a drivewheel assembly 108 and a cutting assembly 126. A motor 122 is connectedto the drive wheel assembly 108 to drive adhesive film 106 therethrough.The adhesive dispensing apparatus 100 further includes a pinch wheelassembly 130 positioned above the drive wheel assembly 108 to hold thecoverlay film 112 between the pinch wheel assembly and the drive wheelassembly 108. A spring-loaded idler roller 142 is positioned to adjustfor slack that may be caused by slippage between the drive wheelassembly and the adhesive film 106.

[0030] More specifically, the adhesive dispensing apparatus 100 of thepresent invention includes one or more film reels 104. The film reel 104may be mounted to a support frame (not shown) in a manner such that thefilm reel is freely rotatable. The film reel 104 is adapted to supplycontinuous lengths of adhesive film 106, either double-sided orsingle-sided adhesive film, including a coverlay film 112. In theillustrative embodiment there is a single film reel 104 shown.Depending, however, upon the application and the number of adhesivestrips 120 required for each die site on the support element 42 (FIG.2A), the apparatus and methods of the present invention may include agreater number of film reels 104.

[0031] The drive wheel assembly 108 of the adhesive dispensing apparatus100 preferably includes driven push wheel 110 and lower push wheel 114.A first spring 118 is positioned substantially vertically relative tolower push wheel 114 and immediately adjacent the lower push wheel 114.First spring 118 urges the lower push wheel 114 toward adhesive film106, providing a pinching or friction force (fpA) such that the lowerpush wheel and the driven push wheel 110 are held tightly againstopposing surfaces of the adhesive film 106.

[0032] The lower push wheel 114 is preferably free floating in theX-axis direction. The driven push wheel 110 is preferably fixed anddrivably connected to a stepper motor 122. The stepper motor 122 isadapted to drive the driven push wheel 110 and, due to frictional forcefpA, the lower push wheel 114, through predetermined complete or partialrevolutions. Each revolution of the driven push wheel 110 and the lowerpush wheel 114 moves the adhesive film 106 a corresponding linearamount. Thus, the drive wheel assembly 108 is operable to feed or indexa predetermined length of adhesive film 106 into the film cuttingassembly 126 for cutting (as discussed below).

[0033] The pinch wheel assembly 130 of the adhesive dispensing apparatus100 preferably comprises an upper pinch roller 134 and second spring138. The pinch wheel assembly 130 is preferably positioned above andimmediately adjacent to the driven push wheel 110 of the drive wheelassembly 108 (see FIG. 3). The upper pinch roller 134 is preferably freefloating along the X-axis direction (as is lower push wheel 114). Thesecond spring 138 is preferably positioned in a substantially verticaldirection, immediately adjacent the pinch roller 134. The second spring138 urges the upper pinch roller toward the driven push wheel 110,thereby providing a pinching or friction force (fpB) between the upperpinch roller 134 and the driven push wheel 110. The pinch wheel assembly130 operates to remove the coverlay film 112 from the adhesive film 106.That is, the coverlay film 112 is removed by the pinch roller 134 byapplication of friction force (fpB) supplied by second spring 138between the pinch roller and the driven push wheel 110. As the drivenpush wheel 110 rotates the coverlay film 112 is peeled away from theadhesive film 106 by a proportional exact amount as the adhesive film ispulled from the film reel 104 and the adhesive 116 is then pushed intothe cutting assembly 126. The coverlay film 112 is pushed through thepinch wheel assembly 130 to the outside of adhesive dispensing apparatus100 for disposal.

[0034] The adhesive dispensing apparatus 100 of the present inventionfurther preferably includes an idler assembly 142 positioned downstreamof the drive wheel assembly 108 and the pinch wheel assembly 130. Theidler assembly 142 includes third spring 144, shaft 146 and an idlerroller 148. The idler roller 148 is urged in a downstream direction bythe third spring 144. The third spring 144 also allows movement of theidler roller 148 in an upstream direction when force is applied to theidler roller by the coverlay film 112. The third spring 144 therebyprovides a push-pull type movement of the idler assembly 142 to allowfor slackening or tightening of the adhesive film 106 (as discussedbelow).

[0035] A film guide (not shown) is formed with a guide channel 150 forreceiving an adhesive film 106 from each film reel 104. In addition, theguide channel 150 may be adapted to maintain a precise spacing andparallel orientation of ribbons of adhesive film 106 as the films arefed and indexed by the drive wheel assembly 108 into the film cutterassembly 126. The film guide may comprise any suitable apparatus such asthat disclosed in U.S. Pat. No. 6,012,502 (incorporated herein byreference). As is explained in U.S. Pat. No. 6,012,502, the film cutterassembly 126 may be configured to enclose and guide the adhesive film106 for cutting into predetermined, exact lengths.

[0036] The adhesive 116 (having had the coverlay film 112 removed)passes through the idler assembly 142 to the cutter assembly 126. Thecutter assembly may comprise any suitable adhesive film cuttingapparatus, such as the apparatus disclosed in U.S. Pat. No. 6,012,502.Referring to FIG. 3, the illustrated cutter assembly 126 includes acutter block 154 mounted on a piston mechanism 164 for reciprocalmovement in the y-axis direction. One or more film cutters 158 and oneor more guide openings 160 are preferably included for aligning theadhesive 116 with the cutting blade 158 and the support element 42. Theguide opening 160 is defined by the cutting blade 158 and opposing siderail 162.

[0037] The piston mechanism 164 preferably includes vacuum passages 168in fluid communication with a vacuum conduit 170. The vacuum conduit 170is in fluid communication with a vacuum source 176 and suitable controlvalves (not shown) for effecting cycling of the vacuum to the vacuumpassages as required.

[0038] The vacuum passages 168 apply a vacuum force to the adhesive 116,thereby securing the adhesive 116 to the cutter block 154 as the cutterblock is moved slightly upward (in the Y-axis direction) to (first)press the adhesive 116 past the cutter blade 158. The cutter block 154is then driven by the piston mechanism 164 further upward to press thecut adhesive strip 120 against the support element 42 (discussed furtherbelow). The piston mechanism 164 is operated by a device, such as apneumatic air actuator or electric motor (not shown).

[0039] A peripheral outline of the cut adhesive strips 120 will matchthe peripheral outline of the guide opening 160. In the illustrativeembodiment the adhesive strips 120 have a generally rectangularperipheral shape. However, other peripheral shapes, such as a square,are also possible. Depending upon the dimensions of the support element42, the corresponding die site, and the width of bond wire slot 64 ofthe substrate 56 (FIGS. 2A-2E), the cutter blade 158 and guide opening160 can be shaped and dimensioned as required.

[0040] The cutter blade 158 is preferably formed with a sharp, burr-freecutting edge for cutting the strips of adhesive. The cutter blade 158preferably includes a finished surface (e.g., 8 micro inches). The siderail 162, defining the guide opening 160, is also preferably formed witha finished surface.

[0041] The support element 42 may be fed and indexed to the film cutterassembly 126 using a conventional support element handling apparatus(not shown), such as the handling apparatus manufactured by ESCManufacturing Company of Warrington, Pa. (e.g., an ESC Apollo 9200 LOCdie attach system). The support element 42 handling apparatus preferablyincludes guide members (not shown) for guiding the support element 42and an indexer walk beam (not shown) for indexing the support element 42to a location for applying the cut adhesive strips 120 to the reject diesites and/or the functional die sites. The support element handlingapparatus preferably includes a heat block to provide heat if necessaryto activate the adhesive strips 120.

[0042] Operation

[0043] Prior to the die attachment process (and the encapsulationprocess), defect substrates (and, thus, reject die sites) are detectedand marked using conventional methods known to those persons skilled inthe art. The cover member 48, such as an adhesive strip 120, may beattached to the reject die sites at a number of different stages duringthe semiconductor package manufacture process. The cover member 48,however, should be attached prior to the encapsulation process.

[0044] The adhesive dispensing apparatus 100 of the present inventionapplies the adhesive strip 120 to reject die sites (and functional diesites if so desired) of the support element 42. The applied adhesivestrip 120 functions as the cover member 48 or may then have a covermember 48 attached thereto (if the adhesive was attached to a reject diesite on the support element). Alternatively, the adhesive dispensingapparatus 100 of the present invention applies the adhesive strip 120 tothe support element 42 to have a functional die attached thereto (if theadhesive strip were applied to a functional die site on the supportelement). The application of the adhesive strip 120 to the supportelement 42 is done synchronously with the removal of the coverlay film112 from the adhesive film 106.

[0045] More specifically, the adhesive dispensing apparatus 100 of thepresent invention pulls the adhesive film 106 from the dispensing reel104 and pushes the adhesive film in a downstream direction (i.e., towardthe cutting apparatus) using friction forces provided by the drive wheelassembly 108. The stepper motor 122 drives the drive wheel assembly 108.The stepper motor 122 is pre-programmed to rotate a specific distance,which in turn pulls an exact amount of adhesive film 106 from the filmreel 104 and pushes an exact amount of adhesive 116 into the cuttingassembly 126.

[0046] The pinching or friction force (fpA) supplied by first spring 118of the drive wheel assembly 108 holds the push wheels 110, 114 tightlyagainst the adhesive film 106. The pinch wheel assembly 130 then removesthe adhesive film's coverlay film 112. That is, as the drive wheelassembly 108 rotates, the coverlay film 112 is peeled away from theadhesive film 106 by a proportional exact amount as it is pulled fromthe film reel 104 and is pushed into the cutting assembly 126.

[0047] The idler assembly 142, by the urging force of the third spring144, removes any slack in the adhesive film 106 that may have beencaused by slippage between the driven push wheel 108 and the adhesivefilm 106. Likewise the idler assembly, by contraction of the thirdspring 144, ensures that the coverlay film 112 does not break or snapdue to the pinch wheel assembly 130 moving the coverlay film morequickly than the drive wheel assembly 108 is moving the adhesive film106. That is, the idler assembly acts as a push/pull system to take upor provide slack as necessary to prevent binding or breakage of thecoverlay film 112.

[0048] The adhesive 116 that is moved into the cutter assembly 126 isthen acted upon by a vacuum force that holds the adhesive 116 on thecutter block 154. The cutter block 154 is then moved in an upward (ory-axis) direction by the piston mechanism 164. As the cutter block 154,with the adhesive 116 held in position by vacuum forces, is movedthrough its upward stroke, the adhesive 116 contacts the cutting blade158 which shears the adhesive into a specific size adhesive strips 120or decals. The cutter block 154 continues to move in an upward directionuntil the adhesive strip 120 contacts the die site on the supportelement 42 (the support element die sites are positioned a specificdistance above the adhesive dispensing apparatus 100).

[0049] The adhesive strip 120 is pressed against the support element diesite with a predetermined specified force. When the support element 42is contacted by the sized adhesive strip 120 mounted on the cutter block154, the forces applied by the pneumatic actuator or electric motorforce cause the adhesive strip 120 to stick to the die site. Inaddition, when contact is made the vacuum that held the adhesive strip120 to the cutter block 154 is removed. The adhesive strip isspecifically placed on the die site to cover from about 70% to about100% of the wire bond slot 64.

[0050] The percentage of coverage of the wire bond slot 64 with thecover member 48 (e.g., adhesive strip 120) may vary depending upon theencapsulation material to be used and the width of the wire bond slot64. Nonetheless, it has been discovered that for most conventionalencapsulation materials and convention slot widths, the cover member 48(e.g., the adhesive strip 120) should cover from about 70% to about 100%of the wire bond slot 64 opening. It has been discovered that when acover member 48 (e.g., the adhesive strip 120) is attached to a rejectdie site 36 to completely cover (i.e., cover 100% of) wire bond slot 64(as shown in FIG. 2D), a negative pressure on the first surface 44 ofthe substrate 56 may occur during the encapsulation process. A negativepressure may cause undesirable bending or bowing of the substrate 56near or at the edges of the wire bond slot 64. It has also beendiscovered that 100% coverage of the wire bond slot 64 opening may workif the cover member (e.g., the adhesive strip 120) material and/or theadhesive (e.g., the adhesive strip 120) for attaching the cover memberto the substrate 56 are sufficiently strong so as to withstand theencapsulation process pressures. It is possible, however, that with somesubstrate materials, the substrate 56 is deformed beyond acceptablelimitations due to the pressures built up when the wire bond slot 64 iscovered completely.

[0051] The optimum percentage of coverage of the wire bond slot 64 withthe cover member 48 (e.g., the adhesive strip 120) will necessarilydepend upon the encapsulation material to be used and the wire bond slot64 width. Nonetheless, it has also been discovered that when a covermember 48 (e.g., the adhesive strip 120) is attached to a reject diesite 36 to cover just a major portion of the bonding slot 64 (i.e., fromabout 70% to about 98% or, more preferably from about 80% to about 95%,and most preferably about 90% coverage of the wire bond slot 64 opening)(see FIG. 2C) encapsulation material bleeding is virtually or completelyeliminated. Furthermore, a negative pressure zone at the substrate 56 isnot created during encapsulation.

[0052] It has also been discovered that when a cover member 48 (e.g.,the adhesive strip 120) is attached to a reject die site 36 to cover aminor portion of the bonding slot 64 (i.e., less that about 65% of thewire bond slot 64 opening (see FIG. 2E) bleeding or flashing oftenoccurs. On the other hand, 65% coverage is better than no coverage ofthe wire bond slot 64 opening. Further, bleeding is most frequently aproblem when the encapsulation material enters the solder ballattachment pad area of the semiconductor package. Semiconductor packageshaving smaller pitches and less space between the solder ball attachmentpads are more susceptible to contamination from encapsulation bleed thanare semiconductor packages having wider pitches or greater spacesbetween the ball attachment pads.

[0053] The indexing, removal of coverlay film, cutting and applicationcycle is repeated for the next adhesive strip 120 application. More thana single adhesive dispensing apparatus 100 of the present invention maybe operated in a side-by-side fashion to apply multiple cover members 48to multiple reject die sites on a support element 42 or to applymultiple adhesive strips 120 to all die sites on a support element.

[0054] Whereas the invention has been described with reference to anumber of embodiments of the apparatus and methods of the presentinvention, it will be understood that the invention is not limited tothose embodiments. On the contrary, the invention is intended toencompass all modifications, alternatives, and equivalents as may beincluded within the spirit and scope of the invention as defined by theappended claims.

I claim:
 1. An apparatus for synchronously removing a coverlay film froman adhesive film and attaching an adhesive strip cut from the adhesivefilm to a support element, comprising: a reel of adhesive film; a drivewheel assembly positioned downstream of the reel of adhesive film andconfigured to index the adhesive film; a pinch wheel assembly positionedimmediately above and adjacent to the drive wheel assembly, the pinchwheel assembly operable in conjunction with the drive wheel assembly toremove the coverlay film from the adhesive film; a cutter assemblypositioned downstream of the drive wheel assembly and the pinch wheelassembly, the cutter assembly comprising an opening having a peripheraloutline defined by a cutting blade and a side rail, the openingconfigured to receive a leading terminal end of adhesive from theadhesive film and a portion of the adhesive following the leadingterminal end, and a channel configured to guide the adhesive into theopening; and a cutting block configured to move through the opening tocut adhesive strips from the adhesive received within the opening and toapply the adhesive strip to the support element, the cutting block andthe adhesive strip having the peripheral outline of the opening.
 2. Theapparatus of claim 1, further comprising an idler assembly positioneddownstream of the drive wheel assembly and the pinch wheel assembly, theidler assembly configured to push or pull the adhesive film as needed toeliminate or add slack to the adhesive film before the coverlay film isremoved therefrom.
 3. An method for synchronously removing a coverlayfilm from an adhesive film and attaching an adhesive strip cut from theadhesive film to a support element, comprising: removing adhesive filmfrom a reel; feeding a portion of the adhesive film through a drivewheel assembly positioned downstream of the reel; indexing the adhesivefilm; removing the coverlay film from the adhesive film using a pinchwheel assembly positioned immediately above and adjacent to the drivewheel assembly and operating in conjunction therewith; feeding a leadingterminal end of adhesive from the adhesive film and the indexed portionof the adhesive following the leading terminal end onto a cutting blockof a cutter assembly after the coverlay film is removed from theadhesive film; and reciprocating the cutting block through an opening tocut adhesive strips from the adhesive received within the opening andapplying the adhesive strip to the support element.